Paving and surfacing material



Patented Au 31, 1926.

CYBIL EDWARD R-KMSDEN', F STOKE-ON-TRENT, ENGLAND.

PAVING A1\TD SURFACING MATERIAL.

No Drawing. Application filed August 19, 1925, Serial No. 51,261, and in Great Britain August 1, 1924.

This invention relates to paving and surfacing material of a green colour adapted to be rammed or rolled to form a coherent sur face layer.

6 Paving or surfacing material of this kind is claimed broadly in the complete specification of my application for British Letters Patent No. 23858 of 1923, which also claims hard-court tennis courts or other areas or '10 spaces for playing games paved or surfaced ed or superficially impregnated with. material imparting to the granules the desired colour.

Preferably the material comprises a col- 2 curing matter which is fixed or formed by firing. Thus, in accordance with the invention the particles of granular material may be coloured green by means of chromium compounds formed by a firing operation.

of forming the paving or surfacing material, which comprises adding to granular material of convenient colour a solution or suspension of a material adapted on firing the granular material to impart to it a green colour.

To effect economy in the consumption of the colouring substances the granular mate rial preferably possesses a low degree of 1? porosity or permeability.

Preferably, highly silicious material is employed as the basis of the paving or surfacing material.

Thus, for instance, in accordance with the invention crushed or ground flint, quartz, quartzite, ganister, sandstone, silica rock, feldspar, Cornwall stone (china stone) and liked naturallyocc-urring materials, may be use Alternatively, other naturally occurring or artificially produced materials of sufiicient hardness to withstand the wear to which the paving or surfacing material will be subjected may be employed and as an example of an artificially produced material previously burnt clay, earthenware, tiles,

The invention also extends to the process china, porcelain, pitchers and other waste ceramic material in an unglazed condition, slags and particularly such as are of a light colour, may be used.

For imparting the green colour to the material, water soluble salts containing chromium are conveniently employed; thus, for instance, bichromate or chromate of soda or potash may be used.

When employing flints these-are with or without previous calcination crushed to the fineness ultimately required in the material. For instance, they may be crushed to pass a quarter-inch ring and then mixed with a suitable proportion of a chromium salt.

For instance, if a bichromate is used 56 lbs. of this material dissolved in water may be added to one ton of crushedfiints.

It will be found that the solution employed may with advantage contain 7 lbs. of bichromate to each gallon of water.

If necessary or desirable a reducing agent,

such as carbon, charcoal, sulphur or the like' may be added to the crushed flint and if necessary an adhesive or a thickening medium may be introduced into the solution,

the adhesive or thickening medium being.

optionally of a reducing character. For this purpose starch, gum, glue, dextrine or the like may be used.

' The mixture obtained with or without previous drying is burnt in a furnace of suitable design at a temperature suflicient to develop the desired colour. If, for instance, the furnace is already at a temperature of about 1000 or more the duration of the heating operation may vary from a few minutes to about one hour; within limits, the higher the temperature or the longer the time during which the material is heated the brighter will be the colour.

After withdrawing from the furnace the burnt or fired material and allowing the same to cool, it may be washed or not as desired. Generally-speaking, it will be found that washing is unnecessary.

The mass withdrawn from the furnace may be somewhat caked but insufiiciently so to render crushing or rinding necessary, the handling to which t e material is subjected in bagging up or loading being usually sufiicient to break down any material which may have become aggregated in the burning operation.

In forming the material in accordance with the invention into a coherent surface agents.

layer or paving, the material may be rammed, rolled or otherwise consolidated without the use of a binder.

Alternately, the material may be employed in association with a binding medium.

The binding medium employed in accordance with the invention may be such as to secure substantially permanent aggregation of the particles to form a mass of the character of concrete or bituminous paving ma terial.

Alternatively, the binding medium may be such as to'merely secure a degree of adhesion between the particles comparable with that characteristic of gravel, and preferably provide a yielding or relatively resilient surface.

The character of the binding medium will vary in accordance with the requirements of particular cases and should be such that it does not cause excessive or material deterioration of the green colour of the granular bodies constituting the aggregate.

As the bindingmedia, resinous or adhesive materials such as rubber, fatty oils or oxidized, blown, polymerized fatty oils,

may be used, in which case the adhesive ma terial may be applied in the form of a solution or emulsion to the surface layer or the particles of the surfacing material may be coated in any other convenient way with the adhesive.

Rubber latex may be employed in accord ance with the invention as also may emulsions of fatty oils or oxidized, blown or polymerized fatty oils in water, prepared with or without the aid of emulsifying Emulsions of bituminous formed with the aid of suitable emulsifying agents such, for instance, as albuminous sub stances or products obtained by breaking down or hydrolyzing albuminous sub stances may also be made use of.

In some cases, in forming solutions of binding media, volatileorganic solvents may be employed while in others non-volatile solvents which may possess the property of drying, hardening or becoming adhesive, may be used.

Where fatty oils or oxidized, blown or polymerized fatty oils are used they may be applied if sufliciently fluid without resort to the use of solvents or diluents.

In one mode of. carrying the invention into effectjthe binding medium is applied materials to the surfacing material after it has been rammed or rolled in a dry or moist state so as to form a coherent layer, the binding agent alone or in the form, for instance, of an emulsion or solution in combination with suitable diluents being sprayed or otherwise distributed over said surface.

In most cases it will be found desirable to employ a proportion of binding medium merely 'suflicient to cause the particles to adhere one to the other Without securing impermeability of the surface to water.

As examples of the materials suitable for use as binders in accordance with the invention and for the purpose of indicating the proportion thereof employed relative to the granular material, the following particulars are given 1. 20 gallons blown linseed oil. granular material.

2. 20 gallons rubber latex. 1 ton granular material.

The blown linseed oil is used without the aid of a solvent or diluent while the rubber 1' ton latex is employed in its commercial state.

rubber solution in the gallons to one ton of granbeen tried, but it is found degrades the colour some- The employment of proportion of 30 ular material has that this material what.

While the invention is mainly concerned with paving hard tennis courts it will be understood that theinvention is also applicable to paving other surfaces, for instance garden paths.

Having now described my invention, what I claim as new and desire to secure by Letters Patent is 1. A paving material comprising crushed granules of material possessing a low degree of porosity combined with a binder of rubber latex of a proportion of substantially 20 gallons of latex to one ton of the crushed granules.

2. A paving material comprising crushed flint combined with a binder of rubber latex of a proportion of substantially 20 gallons of latex to one ton of flint.

A paving material comprising greencolored crushed flint combined with a binder of rubber latex of a proportion of substantially 20 gallons of latex to one ton of flint.

In testimony whereof I have signed my name to this specification.

CYRIL EDWARD RAMSDEN. 

